Re: Incorrect in-kernel bitmap on raid10

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Neil Brown <neilb@xxxxxxx> wrote:
> Could you let me know if that following patch helps?

Hmmm, it looks like the patch doesn't fully fix it.
I told you already about the semi-initialized on-disk bitmap:

root@darkside:~# mdadm -X /dev/sd[cdefgh][1] | grep Bitmap | sort
          Bitmap : 268275 bits (chunks), 137203 dirty (51.1%)
          Bitmap : 268275 bits (chunks), 137203 dirty (51.1%)
          Bitmap : 268275 bits (chunks), 137203 dirty (51.1%)
          Bitmap : 268275 bits (chunks), 137203 dirty (51.1%)
          Bitmap : 268275 bits (chunks), 137203 dirty (51.1%)
          Bitmap : 268275 bits (chunks), 137203 dirty (51.1%)

I tried to clean it up with:
root@darkside:~# echo 0-268275 > /sys/block/md7/md/bitmap_set_bits

This should set all bits, and it seems to do:
root@darkside:~# mdadm -X /dev/sd[cdefgh][1] | grep Bitmap 
          Bitmap : 268275 bits (chunks), 268275 dirty (100.0%)
          Bitmap : 268275 bits (chunks), 268275 dirty (100.0%)
          Bitmap : 268275 bits (chunks), 268275 dirty (100.0%)
          Bitmap : 268275 bits (chunks), 268275 dirty (100.0%)
          Bitmap : 268275 bits (chunks), 268275 dirty (100.0%)
          Bitmap : 268275 bits (chunks), 268275 dirty (100.0%)

However, in-kernel it should also allocate all pages, but it does not:
root@darkside:~# head -4 /proc/mdstat 
Personalities : [raid1] [raid10] 
md7 : active (auto-read-only) raid10 sdc1[0] sdh1[5] sde1[4] sdg1[3] sdd1[2] sdf1[1]
      4395406848 blocks 512K chunks 2 near-copies [6/6] [UUUUUU]
      bitmap: 64/131 pages [256KB], 16384KB chunk

stopping/starting the array doesn't help either:
root@darkside:~# mdadm --stop /dev/md7
mdadm: stopped /dev/md7
root@darkside:~# mdadm -A /dev/md7
mdadm: /dev/md7 has been started with 6 drives.
root@darkside:~# head -4 /proc/mdstat 
Personalities : [raid1] [raid10] 
md7 : active (auto-read-only) raid10 sdc1[0] sdh1[5] sde1[4] sdg1[3] sdd1[2] sdf1[1]
      4395406848 blocks 512K chunks 2 near-copies [6/6] [UUUUUU]
      bitmap: 64/131 pages [256KB], 16384KB chunk
root@darkside:~# sleep 10
root@darkside:~# head -4 /proc/mdstat 
Personalities : [raid1] [raid10] 
md7 : active (auto-read-only) raid10 sdc1[0] sdh1[5] sde1[4] sdg1[3] sdd1[2] sdf1[1]
      4395406848 blocks 512K chunks 2 near-copies [6/6] [UUUUUU]
      bitmap: 0/131 pages [0KB], 16384KB chunk
root@darkside:~# echo 3 > /proc/sys/vm/drop_caches 
root@darkside:~# mdadm -X /dev/sd[cdefgh][1] | grep Bitmap
          Bitmap : 268275 bits (chunks), 137203 dirty (51.1%)
          Bitmap : 268275 bits (chunks), 137203 dirty (51.1%)
          Bitmap : 268275 bits (chunks), 137203 dirty (51.1%)
          Bitmap : 268275 bits (chunks), 137203 dirty (51.1%)
          Bitmap : 268275 bits (chunks), 137203 dirty (51.1%)
          Bitmap : 268275 bits (chunks), 137203 dirty (51.1%)


regards
   Mario
-- 
As a rule, the more bizarre a thing is, the less mysterious it proves to be.
                                    -- Sherlock Holmes by Arthur Conan Doyle

--
To unsubscribe from this list: send the line "unsubscribe linux-raid" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html

[Index of Archives]     [Linux RAID Wiki]     [ATA RAID]     [Linux SCSI Target Infrastructure]     [Linux Block]     [Linux IDE]     [Linux SCSI]     [Linux Hams]     [Device Mapper]     [Device Mapper Cryptographics]     [Kernel]     [Linux Admin]     [Linux Net]     [GFS]     [RPM]     [git]     [Yosemite Forum]


  Powered by Linux